Curtain wall system with vents

ABSTRACT

A curtain wall structure includes common extruded aluminum members which are assembled to form narrow profile vertical and horizontal mullions defining bay frames for supporting panels of glass or other structural panels. Frames for casement operating windows or vents are formed from similar extruded aluminum members, with the vent frames interfitting with the bay frames to maintain the narrow profile appearance of the curtain wall mullions. The common framing members are L-shaped in cross section defining side walls and face walls, with the face walls providing the narrow profile appearance; and are configured so that two framing members interfit with each other to maintain the narrow profile appearance. The framing members include longitudinal grooves which define panel supporting channels in the bay frames, or which retain longitudinal stops defining alternative panel supporting channels.

Eichman CURTAIN WALL SYSTEM WITH VENTS [76] Inventor: Ellis V. Eichman,790 Fruitdale Road, Brownsville, Tex. 78520 [22] Filed: March 5, 1971[21] Appl.No.: 121,277

[52] U.S.Cl. ..52/204,49/504,52/235, 52/397, 52/476 [51] lnt.Cl. ..E04b2/88 [58] Field of Search ..52/207, 235, 397, 204, 476; 49/484, 504,DIG. 1,400,401

[56] References Cited UNITED STATES PATENTS 3,138,229 6/1964 Hubbard..52/400 2,913,778 11/1959 Alexander ..52/207X 2,885,040 5/1959Grossman.... ..52/207 3,140,763 7/1964 Edelstein.... 52/397X 3,403,49110/1968 Eichman ..52/397 3,475,870 1l/1969 Birum,Jr..... ..52/2113,579,939 5/1971 Eichman ..52/397 FOREIGN PATENTS 0R APPLICATIONS229,561 7/1960 Australia ..49/504 1March 13, 1973 866,383 2/1953 Germany..52/207 849,735 9/1960 GreatBritain ..52/207 Primary Examiner-Alfred C.Perham Attorney-Cecil L. Wood and Peter J. Murphy [57] ABSTRACT Acurtain wall structure includes common extruded aluminum members whichare assembled to form narrow profile vertical and horizontal mullionsdefining bay frames for supporting panels of glass or other structuralpanels. Frames for casement operating windows or vents are formed fromsimilar extruded aluminum members, with the vent frames interfittingwith the bay frames to maintain the narrow profile appearance of thecurtain wall mullions. The common framing members are L-shaped in crosssection defining side walls and face walls, with the face wallsproviding the narrow profile appearance; and are configured so that twoframing members interfit with each other to maintain the narrow profileappearance. The framing members include longitudinal grooves whichdefine panel supporting channels in the bay frames, or which retainlongitudinal stops defining alternative panel supporting channels.

9 Claims, 18 Drawing Figures PATENTEDHAR] 31973 SHEET l0? 4 lu u m Fig.3

INVENTOR Ellis V. Eichmon ATTORNEYS PATHHEDHARUIQB 720,025

SHEET 2 [IF 4 k A 4 v QIIIIEV INVENI' OR Ellis V. Eichmcn Fig.lO Fig.llBY M ATTORNEYS PMUHWMRI .1: ms 3.720.025

SHEET 30F 4 Fig.l5

INVENTOR Ellis v. Eichmon ATTORNEYS CURTAIN WALL SYSTEM WITH VENTSBACKGROUND AND SUMMARY OF THE INVENTION This invention relates tocurtain wall systems; and more particularly to a curtain wall andoperating vent structure and assembly.

Applicants prior U.S. Pats., No. 3403491 granted Oct. 1, I968, and No.3,579939 granted May 25, I971 l relate to curtain wall structuressuitable for use as building facades or as exterior or interior walls.These curtain walls may include panels of glass or other structuralpanels which are framed in horizontal and vertical mullions, preferablyfabricated from extruded aluminum, into a form to present a narrowprofile which is aesthetically pleasing. The present invention isconcerned with a vent structure suitable for use with such curtain wallswhich may be hingedly attached to the wall mullions to define a casementvent or operating window without destroying the narrow profileappearance of the wall structure.

In such curtain walls it is frequently desirable to provide vents, suchas casement windows for example, which may be conveniently opened by theoccupants of a building or room enclosure to provide air circulation orventing of the enclosure. At the same time, it is desirable that suchvent or operating window be constructed in the manner to blend into thewall structure and not destroy the aesthetic appearance of the wall orfacade.

An object of this invention is to provide an improved and novel framingstructure for curtain walls and for associated vents. Another object ofthis invention is to provide such a framing structure wherein commonframing members are used for the panel walls mullions and for the ventframes providing for economy of component manufacture and of wallfabrication.

A further object of this invention is to provide a complementarystructure of curtain wall framing and vent framing, to maintain theaesthetic narrow profile of the panel wall mullions in the fixed andvented areas.

Still another important object of this invention is to provide anundetectable vent structure in a curtain wall.

These objects are accomplished in a curtain wall structure whichincludes horizontal and vertical mullions defining at least one bayframe for a casement vent, and wherein framing members of common designare employed in the fabrication of the mullions and of the vent frames.The framing members are L-shaped in cross section defined by side wallsand face walls, with the face walls defining the visible profile of theframing members for the curtain wall structure. The framing members aredesigned to interfit with each other so that a vent frame and ventopening frame are closed in superposed relation to maintain the narrowprofile appearance of the wall structure. The framing members providegrooves defining supporting channels for various types of wall panels.

The novel features and the advantages of the invention, as well asadditional objects thereof, will be understood more fully from thefollowing description when read in connection with the accompanyingdrawings.

DRAWINGS FIG. 1 is a fragmentary view of a building face provided with awall opening in which is mounted a curtain wall and inward openingcasement vent structure ac cording to the invention;

FIGS. 2, 5 and 7 are fragmentary sectional views taken in the indicatedplanes in FIG. 1 illustrating the peripheral frame members for thecurtain wall as- 0 sembly and the means for mounting the curtain wallwithin the building wall opening;

FIGS. 3, 4 and 6 are fragmentary sectional views taken in the indicatedplanes in FIG. 1 illustrating the curtain wall framing for the ventopening, the vent frame, and the coacting relation thereof;

FIG. 8 is a fragmentary sectional view taken in the plane 8-8 of FIG. 1illustrating a horizontal frame bar for the vent;

FIG. 9 is a fragmentary view of the vent latch illustrated in FIG. 3, asviewed from the interior face of the curtain wall;

FIGS. 10 and 11 are fragmentary sectional views taken in the plane 10-10of FIG. 1 illustrating the vent in the closed and open positionsrespectively;

FIG. 12 is a fragmentary view of a building wall showing an outwardopening casement vent and associated framing mounted within an openingin the building wall;

FIGS. 13, 14, 15 and 16 are fragmentary sectional views taken in theindicated planes in FIG. 12 illustrating the framing for the ventopening as mounted within the building wall opening, the vent frame, andthe coacting relation thereof;

FIG. 17 is a fragmentary view of a fixed window mounted within abuilding wall opening; and

FIG. 18 is a fragmentary sectional view illustrating the mounting of thefixed window pane and frame within the building opening, as viewed inany of the planes 18-18 in Fig. 17.

DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1 of the drawing thereis shown a curtain wall structure 10 provided in an opening 11 in amasonry wall 12, for example, as viewed from the exterior of the masonrywall. The curtain wall is made up of vertical mullions 13 and horizontalmullions 14, with the mullions defining bays within which are mountedwall panels, which may be glass panes 15 in the case of a windowstructure, or which may be other types of architectural panels 16wherein opaque wall structure is desired, for example. The peripheralmullions of the illustrated curtain wall 10 are suitably secured withinthe masonry wall opening 11.

A vent 20, illustrated as a framed casement window, is hingedlysupported within a curtain wall bay defined by the mullions 13b, 13c,14b and 14a. The vent frame 20 includes vertical frame members 210 and21b and horizontal frame members 220 and 22b (not seen in FIG. 1) and ahorizontal bar 23 supporting respective upper and lower glass lights orpanes 24a and 24b.

Except as noted presently, all of the above-mentioned vertical andhorizontal mullions and vertical and horizontal vent frame members arefabricated essentially from desired lengths of a common form of framingmember of the same face width which is preferably an extrusion of asuitable aluminum alloy having the configuration which will now bedescribed with particular reference to FIG. 2, and which is illustratedin the sectional views of the several mullions and vent frames. Thisframing member is generally L-shaped in cross section, the L-shape beingdefined by a side wall 31 and a face wall 32. In the usual construction,the side walls lie in planes transverse to the plane of the curtain wallwhile the face walls of the framing members lie parallel to the plane ofthe wall and define the visible profile of the mullions between theseveral wall panels. By way of example, the width of the face wall maybe about one inch while the width of the side wall may be about twoinches.

The distal edge 33 of the framing member defines an edge wall parallelto and facing oppositely from the outer face of the face wall.

An outer facing shallow groove 34 is provided in the outer face of theside wall 31, adjacent to its intersection with the face wall 32, withthe confronting side wall of this outer facing groove 34 being providedwith confronting dove tail grooves for a purpose to be described. Aninner facing shallow groove 35 is provided in the inner face of the sidewall 31 adjacent to the distal edge 33 and being laterally offset fromthe outer facing groove 34. This inner facing groove is undercut, theconfronting side walls being provided with confronting undercut grooves,also for purposes to be described. At the distal edge of the face wall32, an inwardly directed rib 36 is provided and includes a dove tailgroove opening to the inner face which is parallel with the outerprofile face of the face wall 32.

As will be described subsequently, the outer facing grooves 34 and theinner facing grooves 35 may be employed to define peripheral channelsfor accommodating and supporting relatively thin panels of glass orother material in the bays defined by the framing members. As isparticularly illustrated in FIG. 2, the framing members may also beemployed to accommodate and support a relatively thick architecturalpanel 16 which may be a laminated structure including exterior facesheets 40 and an interior core 41 of thermal insulation material forexample.

To define a supporting channel for a thick panel 16, a face stop 43 ismountable on the framing member defining a face wall confronting theface wall 32. The face stop 43 is an elongated strip of a suitableresilient metal, L-shaped or angle-shaped in cross section, as definedby a face wall 44 and a base wall 45. The base wall 45 includes parallelresilient ribs for locking engagement in the undercut inner facinggrooves 35, whereby the face stop 43 is interlocked with the framingmember 14a with the outer surface of the stop face wall 44 defining acontinuation of the edge wall 33 of the framing member. The distal edgeof the stop face wall 44 is provided with an inward facing rib 46 which,in the interlocked relation, confronts the rib 36 of the face wall 32.The interlocked framing member 14a and face strip 43 then define aninner facing channel for accommodating and supporting the architecturalpanel 16, with the projecting ribs 36 and 46 defining undercuts forretaining sealant material 48 such as a silicone for sealing the panelwithin its supporting peripheral channel. As best seen in FIGS. 2 and 5,the

thick panel 16 is supported centrally in a mullion defined by a framingmember and coacting face stop 43.

In certain situations such as illustrated for the vent fixed bar 23 inFIG. 8, it is desired to provide a retaining channel for a relativelythin panel or pane which is opposite or in the same plane as a panesupported in the outer facing groove 34. For this purpose a filler stop50 is provided, being so designated because it fills out the rectangularcross sectional form of the mullion or framing member, defining a facewall and a portion of a side wall opposite from the side wall 31 of thebase framing member.

As best seen in FIG. 8, a filler stop member 50 is generally achannel-shaped member fabricated of a suitable resilient metal such asan extruded aluminum alloy and defining a face wall 51, a side wall 52and a groove wall 53. The free edges of the face wall 51 and the groovewall 53 define resilient lips for locking engagement with the undercutinner facing groove 35 of the framing member to retain the filler stopin the desired relation wherein the face wall 51 defines a continuationof the edge wall 33 and wherein the groove wall 53 as placed in theconfronting relation with the face wall 32. In the vent bar 23 use ofthe base framing member, illustrated in FIG. 8, the outer facing groove34 defines in part the supporting channel for the pane 24a with the panebeing sealed in the channel with a suitable sealant material. Anopposite facing groove for accommodating and supporting the lower ventpane 24b is defined by the face wall 32 of the base framing member andthe groove wall 53 of the filler stop 50. The groove wall is providedwith a rib 54 confronting the face wall rib 36, with the rib 54 beingprovided with a similar dove tail groove to assist in retaining thesealant material for retaining the panes or other wall panels within theretaining channels.

Filler stop members 50 are also used with certain framing members tosupport the fixed panes 15, as seen in FIG. 7.

It will be noted then that the face stop 43 and the filler stop 50represent alternative components which may be used with the base framingmember to define respectively a relatively wide, central support channelfor relatively thick panels, or a relatively narrow supporting channelopposite from the outer facing groove 34 for relatively thin panels.

FIG. 3 illustrates a situation where a relatively thick panel 16 isabutted against the outer face of the base framing member edge wall 31;and in this situation the coacting edge of the panel 16 is particularlyformed to be received in the relatively narrow outer facing groove 34which then defines a retaining channel for the panel 16. In this case,the panel is sealed with a suitable sealant 48 provided in the groove 34at one face only of the panel 16.

Referring now to the overall curtain wall structure, the outer frame isdefined by upper and lower horizontal mullions 14a and 14f respectivelyand vertical side mullions 13a and 13d respectively. As seen in thefragmentary sectional views of FIGS. 2, 5 and 7, the outer faces of theframing member side walls 31 confront the faces of the masonry wallopening 11; and the framing members are secured to the masonry wallthrough suitable anchoring screws 56 threaded into wooden inserts 57 inthe masonry wall for example, as seen in FIG. 5. Furring or spacerstrips 58 are provided to square the curtain wall opening, and asuitable calking or sealant 59 is provided for sealing the outer framerelative to the masonry wall.

The intermediate vertical mullions 13b and 13c and horizontal mullions14b through 14c, along with the above mentioned mullions 14a, 14f, 13aand 13d, define bay frames for supporting the several panels of thecurtain wall structure; and one bay frame forms the vent opening definedby the head mullion 14b, jamb mullions 13b and 130 and sill mullion 14e.

Since FIG. 1 is a view from the exterior of the building wall 12 and thevent opens inward, the peripheral vent frame members include upper andlower members 22a and 22b respectively which are disposed behind thehead 14b and sill Me, and side members 21a and 21b which are disposedbehind jambs 13b and 130 respectively. The horizontal vent bar 23 is ofcourse visible in FIG. 1, appearing as a continuation of the horizontalmullions 14c and 14d.

The relatively thick architectural panels 16 are mounted in the upperand lower rows of bays which are above and below the vent opening; andthe mounting of these panels 16 is particularly illustrated in FIGS. 2,3, 4 and 5. Glass panes are mounted in the bay frames at the left andright sides of the vent opening; and the manner of mounting the glasspanes is particularly illustrated in FIGS. 6 and 7.

Referring to the relationship between the framing members defining thevent opening and the framing members defining the vent frame, it will benoted from FIGS. 3, 4 and 6 that the framing members for the ventopening are arranged in a manner that the inner surfaces of the sidewalls 31 are confronting, and the face walls 32 therefor define aninwardly directed peripheral flange as well as defining the vent openingprofile as viewedfrom the building exterior.

Conversely, the framing members defining the outer frame for the ventare arranged so that the outer faces of the framing member side walls 31are confronting with the face walls 32 defining an outwardly directedperipheral seating flange, with this vent flange coinciding with theprofile of the vertical mullions 13b and 130 and the horizontal mullions14b and 14c as viewed from the interior of the curtain wall structure.In the assembled relation of the vent frame within the vent opening,then, the peripheral lip defined by the edge walls 33 of the vent framemembers confronts a peripheral sealing seat defined by the face wallribs 36 of the framing members for the vent opening. A suitablecompressable gasket strip 61 may be secured within the dove tail grooveof the ribs 36 to form a resilient exterior closure seal 61 between thevent and the vent opening frame. Similarly, a peripheral sealing seatdefined by the face wall ribs 36 of the vent framing members support aresilient compressible gasket strip 62 to define an interior resilientseal 62 coacting with the peripheral sealing lip defined by the edgewalls 33 of the vent opening framing members.

The vent is swingably supported within the vent opening by articulatinghinges 65 connected between the jambs 13b and 13c and the vent sideframe members 21a and 21b respectively. As best seen in FIG. 6, thehinges 65 are completely enclosed and concealed between the jamb andvent frame when the vent frame is in the closed position. FIGS. 10 and11, which are side views of a curtain wall structure, illustrate thevent in the closed and open positions respectively. As

5 seen in FIG. 11, the vent swings inwardly and downwardly relative tothe building wall structure; and a latch 56 is mounted on the upper ventframe member 220 for latching engagement with the vent head 14b in theclosed position, as illustrated in FIG. 3. Alternatively, latches may bemounted on the jambs for suitable locking with the vent frame.

FIGS. 12 through 16 illustrate another form of vent and curtain wallstructure according to the invention, with the vent frame and the framefor the vent opening being fabricated of the same framing membersalready described.

FIG. 12 is a view from the exterior of a building wall which may be amasonry wall 70 having an opening 71 in which is mounted the framing forthe vent opening. In this illustrated embodiment, there are noadditional fixed panels surrounding the vent opening. The frame for thevent opening includes a head 72, side jambs 73 and 74 and a sill 75. Inthis construction, as seen in the sectional views 13 through 16, thevent is an outward swinging vent, and the opening frame members aremounted with their respective side walls 31 disposed in confrontingrelation with the surfaces of the wall opening 71, with the respectiveface walls 32 defining an inwardly directed peripheral flange at theinterior plane of the vent opening frame. The opening frame members areanchored to the masonry wall structure in the manner previouslydescribed through the use of furring strips and anchor screws threadedinto suitable used to provide a weather seal between the frame membersand the wall opening.

The frame for a vent 80, as viewed in FIG. 12, includes upper and lowerframe members fill and 82 respectively and side members 83 and 84. Thevent structure is essentially identical to that previously describedwith the outer faces of the framing member side walls 31 beingconfronting and the respective outer facing grooves 34 defining achannel for accommodating and supporting a glass pane 85 retainedtherein with a suitable sealant or glazing compound 86. The face walls32 of the vent frame members form an outwardly directed peripheralflange which defines the profile of the entire vent structure 80 asviewed from the exterior of the wall 70.

The vent 80 is a side swinging vent; and for this purpose is pivotallysupported within the frame opening by means of a pair of concealedarticulating hinges 90 of the type previously described which aremounted respectively between the vent opening head 72 and the vent upperframe 81, and between the vent sill 75 and the vent lower frame member82. FIG. 14 illustrates the lower hinge 90 which, in the closedcondition of the vent 80, is confined within the frame enclosure definedby the sill 75 and the vent lower frame member 82.

FIG. 15 of the drawing illustrates the latching jamb 73 of the openingframe and the latching vent frame member 83 upon which is mounted thelatch 91 for latching the vent in the closed position and which mayfunction in a manner similar to a conventional latch for a double hungwindow.

anchors, and with a suitable sealant or calking being The vent frame 80may be fabricated as a welded construction; and to provide additionalrigidity to the vent frame, reinforcing angles 92 may be provided at thecorners of the frame structure, such reinforcing angles being receivedwithin the inner facing grooves 35 of the vent framing member side walls31 and secured to the framing members as by welding. Alternatively, thevent frame and reinforcing angles may be mechanically assembled andfastened.

It may be desirable to include reinforcing angles, such as the angles 92for either the vent frame or for other framing structures described,particularly when the frame openings are relatively large. Consideringthat a typical framing member may have a width of only one inch acrossthe face wall and a depth of only two inches across a side wall, it willbe appreciated that frames defined by such framing members are notmassive, particularly in relation to a relatively large vent or otherframe structure.

. As with the vent frame and the vent opening frame of FIG. 1, theseframes according to the embodiment of FIG. 12 are of identicaldimensions so that the vent frame, which is at the exterior of thebuilding wall in this embodiment, defines the profile for the entirevent framing structure. From the interior of the building wall, the ventopening frame would define the same profile; however, in this formadditional filler strips 93 are secured to the vent opening frame toextend the profile to the interior face of the building wall 70 which isconsiderably thicker than the curtain wall structure. As seen in thedrawings, these filler strips which may be fabricated of an extrudedaluminum alloy, may be joined to the face walls of the vent openingframing members by means of suitable metal screws 94.

Exterior and interior seal gaskets 96 and 97 respectively provide aweather seal between the vent and vent frame opening in the mannerdescribed previously.

FIGS. 17 and 18 of the drawing illustrate a fixed window structure whichmay be mounted in an opening 101 in a wall 100. The frame for this fixedwindow is fabricated from the same framing members already describedincluding upper and lower frame members 102 and 103 respectively andside frame members 104 and 105. These members are secured in a wallopening 101 in the same manner as the vent opening frame for thestructure of FIG. 12. As seen in FIG. 18, which is a cross sectionrepresentative of any of the frame members, the frame is mountedadjacent to the exterior of the wall face, with the face walls 32 of theframing members extending inward so that the pane 106 is mounted fromthe exterior of the building wall 100. The channel for retaining thepane 106 is defined by the face walls 32 of the frame members and fillerstops 50, as described with reference to the embodiment of FIG. 1, whichare retained within the inner facing grooves 35 of the framing members.The face walls 51 of the filler stops 50 along with the edge walls 33 ofthe framing members define the face profile for the window frame asviewed from the building wall exterior. Again, due to the thickness ofthe building wall, filler strips 93 are secured in the wall opening 101to define the face profile for the window frame from the interior of thebuilding wall.

In all of the above-described structures, common framing members areemployed to define the base members for curtain wall mullions, the frameopenings for casement type operating windows or vents, and the framesfor the casement windows or vents. However, a slighly modified framingmember structure may be desired for lower or sill members for thepurpose of draining water which may collect due to seal leakage orcondensation for example. Such a modified structure is shown for thesill l4e for the vent 20 in FIG. 4. In this modified structure a rib 37is formed on the inner surface of the side wall 31 forming a wallgenerally parallel to the face wall 32 and defining, with the face wall,a channel 38 facing oppositely from the outer facing side wall channel34. This channel functions as a moisture collection channel for the sillmember He; and a weephole 39 extends through the face wall 32 to drainmoisture from this channel to the exterior of the curtain wall structurein this embodiment. As seen in FIG. 4, moisture which may leak throughthe vent seal defined by the gasket 61 would be collected in the channel38 and drained as it is collected.

Referring to FIG. 5, a similar modified framing member 14f is employedas a lower frame member for the entire curtain wall structure. Here themoisture collecting channel 38 and the weepholes 39 would drain moisturewhich may leak through the sealant material supporting the panels 16 inthe framing mullions, to the exterior of the curtain wall.

Referring to FIG. 14 of the drawing, the embodiment of FIG. 12 presentsa slightly different situation where the vent is an outward swingingvent, and the vent frame is self-flashing relative to the vent openingframe. In this arrangement, condensation moisture may collect on theinterior surface of the vent pane 85, may leak through the interior sealdefined by the interior gasket 97 for the vent opening frame and draininto the inner facing channel 35 which opens upward in thisconfiguration. To drain this moisture, a plurality of weepholes 39a areprovided communicating the groove 35 with the exterior face of the edgewall 33 to drain to the exterior.

A particular feature of the invention, as described with reference tothe several embodiments, is that common framing members may be employedto define a casement vent frame and the frame opening for supporting thevent, wherein the framing members coact with each other to define anarrow, aesthetically pleasing profile when viewed from either side ofthe wall structure within which the vent is mounted. A further featureof this structure is that these coacting framing members provide for adouble sealing arrangement between the vent frame and the vent openingframe. Still another feature of the invention is that the framingmembers define a box structure wherein the supporting hinges for thevent are enclosed and sealed when the vent is in the closed position,further, contributing to the aesthetic value of the curtain wallstructure.

Another feature of the invention is that the same framing members whichare useful in fabricating the casement vent frames and opening framesare also suitable for the other framing members or mullions of a curtainwall structure, resulting in economic manufacture of curtain wallcomponents and in fabrication of the curtain wall structure.

Another feature of the invention is that the same common framing membersare designed for use with accessory structures for the purpose offraming panels of various types and thickness in a curtain wallstructure such as glass panes and various forms of architectural panels.

While preferred forms of the invention have been illustrated anddescribed, it will be understood by those skilled in the art thatchanges and modifications may be resorted to without departing from thespirit and scope of the invention. For example, while reference is madeto horizontal and vertical mullions and other frame structures, theinvention may be embodied as well in structures in which the mullionsare disposed at angles relative to the horizontal and to the vertical.

What is claimed is:

1. A curtain wall structure comprising vertical and horizontal mullionsdefining at least one bay frame; said mullions comprising elongatedframing members;

a vent frame comprising elongated vertical and horizontal framingmembers;

said framing members for said bay frame and said vent frame being commonto each other; each of said common framing members comprising a unitarymember of generally L-shaped cross section defined by a side wall and atransverse face wall, said face wall defining a face profile of saidmember;

and said vent frame being dimensioned to interfit with a bay framewherein the bay frame face walls and vent frame face walls are disposedin superposed relation whereby said vent frame is substantially mergedwith said bay frame as viewed from a face of the curtain wall structure,with the distaledges of respective side walls confronting the face wallsof the interfitting frame member to define a box frame structure.

2. A curtain wall structure as set forth in claim 1 wherein said boxframe structure defines an enclosed chamber for enclosing and concealingan articulating hinge for supporting the vent frame relative to the ventopening frame.

3. A curtain wall structure as set forth in claim 1 wherein the distaledge of a framing member side wall defines an edge wall for confrontingsealing engagement with the face wall of an interfitting framing member.

4. A curtain wall structure as set forth in claim 3 including seal stripmeans mounted on the inner surface of said framing member face wall forsealing engagement with the interfitting edge wall.

5. A curtain wall structure as set forth in claim 1 wherein the framingmember side wall includes inner and outer facinglongitudinal grooves forproviding panel supporting channels in the frames defined by saidframing members.

6. A curtain wall construction as set forth in claim 5 wherein saidinner facing groove is disposed adjacent to the distal edge of said sidewall and is provided with confronting undercut side walls;

and elongated stop members for interlocking engagement with said framingmembers; said stop members having resilient oppositely facing lips forlocking engagement with said undercut inner facing grooves; said stopmembers providing a face wall op qsite from the framing member face walland de inmg, with the framing member face wall, a

groove providing a panel receiving channel;

and said stop member and framing member defining an edge profilecorresponding in width to the edge profile defined by the framing memberface wall.

7. A curtain wall structure as set forth in claim 6 wherein said stopmember face wall exterior surface defines a continuation of the framingmember edge wall.

8. A curtain wall structure as set forth in claim 6 wherein said outerfacing groove defines a panel supporting channel adjacent to the facewall;

and wherein said stop member defines, with the face wall, an innerfacing panel supporting groove directly opposite said outer facinggroove; said stop member coacting with said framing member to define aface wall profile opposing the framing member face wall profile, and apartial side wall opposing the framing member side wall.

9. A curtain wall structure as set forth in claim 1 said structurecomprising a plurality of bay frames, defined by said vertical andhorizontal mullions, and at least one of said vent frames; and saidmullions and said vent frame framing members defining undisturbedprofile lines.

1. A curtain wall structure comprising vertical and horizontal mullionsdefining at least one bay frame; said mullions comprising elongatedframing members; a vent frame comprising elongated vertical andhorizontal framing members; said framing members for said bay frame andsaid vent frame being common to each other; each of said common framingmembers comprising a unitary member of generally L-shaped cross sectiondefined by a side wall and a transverse face wall, said face walldefining a face profile of said member; and said vent frame beingdimensioned to interfit with a bay frame wherein the bay frame facewalls and vent frame face walls are disposed in superposed relationwhereby said vent frame is substantially merged with said bay frame asviewed from a face of the curtain wall structure, with the distal edgesof respective side walls confronting the face walls of the interfittingframe member to define a box frame structure.
 1. A curtain wallstructure comprising vertical and horizontal mullions defining at leastone bay frame; said mullions comprising elongated framing members; avent frame comprising elongated vertical and horizontal framing members;said framing members for said bay frame and said vent frame being commonto each other; each of said common framing members comprising a unitarymember of generally L-shaped cross section defined by a side wall and atransverse face wall, said face wall defining a face profile of saidmember; and said vent frame being dimensioned to interfit with a bayframe wherein the bay frame face walls and vent frame face walls aredisposed in superposed relation whereby said vent frame is substantiallymerged with said bay frame as viewed from a face of the curtain wallstructure, with the distal edges of respective side walls confrontingthe face walls of the interfitting frame member to define a box framestructure.
 2. A curtain wall structure as set forth in claim 1 whereinsaid box frame structure defines an enclosed chamber for enclosing andconcealing an articulating hinge for supporting the vent frame relativeto the vent opening frame.
 3. A curtain wall structure as set forth inclaim 1 wherein the distal edge of a framing member side wall defines anedge wall for confronting sealing engagement with the face wall of aninterfitting framing member.
 4. A curtain wall structure as set forth inclaim 3 including seal strip means mounted on the inner surface of saidframing member face wall for sealing engagement with the interfittingedge wall.
 5. A curtain wall structure as set forth in claim 1 whereinthe framing member side wall includes inner and outer facinglongitudinal grooves for providing panel supporting channels in theframes defined by said framing members.
 6. A curtain wall constructionas set forth in claim 5 wherein said inner facing groove is disposedadjacent to the distal edge of said side wall and is provided withconfronting undercut side walls; and elongated stop members forinterlocking engagement with said framing members; said stop membershaving resilient oppositely facing lips for locking engagement with saidundercut inner facing grooves; said stop members providing a face wallopposite from the framing member face wall and defining, with theframing member face wall, a groove providing a panel receiving channel;and said stop member and framing member defining an edge profilecorresponding in width to the edge profile defined by the framing memberface wall.
 7. A curtain wall structure as set forth in claim 6 whereinsaid stop member face wall exterior surface defines a continuation ofthe framing member edge wall.
 8. A curtain wall structure as set forthin claim 6 wherein said outer facing groove defines a panel supportingchannel adjacent to the face wall; and wherein said stop member defines,with the face wall, an inner facing panel supporting groove directlyopposite said outer facing groove; said stop member coacting with saidframing member to define a face wall profile opposing the framing memberface wall profile, and a partial side wall opposing the framing memberside wall.